Abstract
The correlation energy (the exact energy minus the Hartree-Fock energy) of an electron gas with a high and slowly varying density is examined. The term proportional to the square of the density gradient is evaluated by the application of perturbation theory to the external field and of the random-phase (or high-density) approximation to the Coulomb interaction. This term has the form $\ensuremath{\Delta}{E}_{c}[\ensuremath{\rho}]=\ensuremath{\int}{d}^{3}xB(\ensuremath{\rho}(x)){|{\ensuremath{\nabla}}_{\ensuremath{\rho}}(x)|}^{2}$, where $\ensuremath{\rho}(x)$ is the electron density. $B(\ensuremath{\rho})$ is found, by summing the leading divergent diagrams, to be $[8.470\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}+O({\ensuremath{\rho}}^{\ensuremath{-}\frac{1}{3}}\mathrm{ln}\ensuremath{\rho})+O({\ensuremath{\rho}}^{\ensuremath{-}\frac{1}{3}})]{\ensuremath{\rho}}^{\ensuremath{-}\frac{4}{3}}$ Ry, with the length measured in units of the Bohr radius. The role of the density gradient in the correlation energy problem of atoms is discussed.
Keywords
Related Publications
Correlation Energy of a Free Electron Gas
The limits of validity of the correlation-energy calculations in the regions of high density, low density, and actual metallic electron densities are discussed. Simple physical ...
Generalized gradient-expansion approximation for the exchange energy
In this work we have studied the generalized gradient-expansion approximation (GGA) for the exchange energy proposed by Perdew to each order up to O(${\mathrm{\ensuremath{\nabla...
Accurate and simple density functional for the electronic exchange energy: Generalized gradient approximation
The electronic exchange energy as a functional of the density may be approximated as ${E}_{x}[n]={A}_{x}\ensuremath{\int}{d}^{3}r{n}^{\frac{4}{3}}F(s)$, where $s=\frac{|\ensurem...
Spin scaling of the electron-gas correlation energy in the high-density limit
The ground-state correlation energy per particle in a uniform electron gas with spin densities ${\mathit{n}}_{\mathrm{\ensuremath{\uparrow}}}$ and ${\mathit{n}}_{\mathrm{\ensure...
Spontaneous creation of almost scale-free density perturbations in an inflationary universe
The creation and evolution of energy-density perturbations are analyzed for the "new inflationary universe" scenario proposed by Linde, and Albrecht and Steinhardt. According to...
Publication Info
- Year
- 1968
- Type
- article
- Volume
- 165
- Issue
- 1
- Pages
- 18-31
- Citations
- 415
- Access
- Closed
External Links
Social Impact
Social media, news, blog, policy document mentions
Citation Metrics
Cite This
Identifiers
- DOI
- 10.1103/physrev.165.18